Direct ray tracing of Phong Tessellation

There are two major ways of calculating ray and parametric surface intersections in rendering. The first is through the use of micropolygons, and the second is to use parametric surfaces such as NURBS surface together with numerical methods such as Newton Raphson. Both methods are computationally expensive and complicated to implement. In this paper, we introduce a direct ray tracing method for Phong Tessellation. Our method gives analytic solutions that can be readily derived by hand and enables rendering smooth surfaces in a computationally inexpensive yet robust way.